Will there be another human influenza pandemic? The certainty is that there will be, and the probability is that the virus will emerge from Eurasian aquatic bird reservoirs and involve reassortment between a human and avian strain, with accumulation of mutations or true recombinational events (or both) that will permit spread and pathogenicity among humans. This process will probably occur in pigs because they possess receptors for both avian and human influenza viruses, and emergence may occur in southern China. Prediction of the subtype is impossible, but there is a hypothesis based on seroarcheology that only H1, H2, and H3 subtypes can infect humans; however, it is arguable that H7 or H2 strains might be equally capable of infecting humans.